The cultivation of genetically modified （GM） plants requires the reduction of an unwanted spread of genes （biological confinement）. Cytoplasmic male sterility （CMS） inhibits the development of functional pollen,...The cultivation of genetically modified （GM） plants requires the reduction of an unwanted spread of genes （biological confinement）. Cytoplasmic male sterility （CMS） inhibits the development of functional pollen, but nuclear restorer （RJ） genes and environmental impacts can restore the fertility. The aim of this study was to verify whether CMS in maize hybrids is a reliable confinement method for the prospective cultivation of GM maize in Germany. Two-year field experiments in three different environments were conducted with three CMS maize hybrids which vary in the CMS stability, one conventional maize variety （all yellow kernels） and white maize as pollen recipient. Tassel characteristics, pollen vitality and cross-pollination rates were investigated. The CMS stability was dependent on the genotype and the specific weather conditions per year and location. In all maize hybrids CMS was unstable. One CMS maize hybrid showed a high level of CMS stability and very low cross-pollination rates in any case （〈 1%）. The two other CMS maize hybrids developed more fluctuant and fertile tassels with few or many pollen, respectively. Compared with a conventional and fully fertile maize variety, cross-pollination of all CMS maize hybrids was strongly reduced （84%-99%）. In conclusion, the CMS trait can be proposed as a useful biological confinement method to reduce pollen-mediated gene flow from GM maize.展开更多
文摘The cultivation of genetically modified （GM） plants requires the reduction of an unwanted spread of genes （biological confinement）. Cytoplasmic male sterility （CMS） inhibits the development of functional pollen, but nuclear restorer （RJ） genes and environmental impacts can restore the fertility. The aim of this study was to verify whether CMS in maize hybrids is a reliable confinement method for the prospective cultivation of GM maize in Germany. Two-year field experiments in three different environments were conducted with three CMS maize hybrids which vary in the CMS stability, one conventional maize variety （all yellow kernels） and white maize as pollen recipient. Tassel characteristics, pollen vitality and cross-pollination rates were investigated. The CMS stability was dependent on the genotype and the specific weather conditions per year and location. In all maize hybrids CMS was unstable. One CMS maize hybrid showed a high level of CMS stability and very low cross-pollination rates in any case （〈 1%）. The two other CMS maize hybrids developed more fluctuant and fertile tassels with few or many pollen, respectively. Compared with a conventional and fully fertile maize variety, cross-pollination of all CMS maize hybrids was strongly reduced （84%-99%）. In conclusion, the CMS trait can be proposed as a useful biological confinement method to reduce pollen-mediated gene flow from GM maize.
